Grease compositions



Patented Sept. 15, 1953 UNITED STATES PATENT OFFICE GREASE COMPOSITIONSHarold A. Woods and Loren C. Bollinger, Martinez, Calif., assignors toShell Development Company, Emeryvillc, Calif., a corporation of DelawareNo Drawing. Application December 29, 1951, Serial No. 264,231

11 Claims. 1

This invention relates to special grease compositions. More particularlyit is concerned with greases resistant to'the solvent action of waterand of light hydrocarbons such as gasoline.

In the lubrication of metal connections for pipe lines and flexiblemetallic hoses and the like, difficulties are encountered when the fluidcarried by the pipe line dissolves the lubricant away from theconnections. This becomes a matter of great concern in militaryapplications and especially for such purposes as fuel transfer betweenplanes during flight. Greases comprising ordinary metallic soaps andmineral lubricating oils are, much too gasoline sensitive to be used forsuch purposes. On the other hand, it is undesirable to have a greasewhich is entirely insoluble in gasoline or water since between periodsof use the grease forms hard metallic residues which plug theconnections and cause other difficulties of operation. A number ofgreases have been proposed for use on apparatus such as valveconnections and the like wherein the grease is composed substantiallyentirely of gasoline-resistant ingredients. Hence, the art has proposedthe use of greases which are known to be too sensitive to the action ofgasoline for critical uses such as inflight transmission of fuel and, onthe other hand, has proposed lubricants which are substantiallyinsoluble in both water and gasoline.

It is an object of the present invention to provide greases which areresistant to washing away by the action of gasoline or water but whichare not entirely insoluble therein. It is another object of thisinvention to provide greases for temporary use and which do not causethe formation of hard metallic residues. Other objects will becomeapparent during the following discussion.

Now, in accordance with the present invention, it has been found thatgasoline and water resistant greases may be formed by utilizing as themajor liquid components a mixture of a water soluble polyoxyalkylenefluid and a partial ester of a polyhydric alcohol having less than sixcarbon atoms with a higher fatty acid. Additionally, it has beendetermined that other advantages are gained by the presence of acombination of an aromatic amine and a substituted oxazoline, all asmore particularly described hereinafter. More specifically a greasehaving optimum propertie comprises a gelling amount of an amine soap ofa higher fatty acid. The latter type of soap is preferably dispersed ina partial ester of a higher hydroxy fatty acid mixed with a watersoluble polyoxyalkylene compound. The chief advantages gained by the useof this type of composition comprise the essentially gasoline and waterresistant character of the entire composition while, at the same time,the amine soap leaves a soft residue which tends to be flushed away to alarge extent during use in the transmission of gasoline, or other lighthydrocarbon, thus leaving a film on the connecting parts of the mixtureof gasoline resistant lubricants, namely, the partial ester and thepolyoxyalkylene fluid. Hence, this type of composition comprises anadvance over the two types of greases already proposed, namely, thosewhich are sensitive in both the fiuid and gelling components to thesolvent action of gasoline and the opposite type of composition which isentirely insoluble in light hydrocarbons and water.

The soaps The soaps with which the present invention is concernedcomprise particularly the hydroxyalkylarnine soaps of higher fattyacids. Preferably, these fatty acids have at least 12 carbon atoms andoptimum results are obtained when the fatty acid has between 16 and 20carbon atoms. While satisfactory results may be obtained with ordinarysaturated fatty acids, the best solubility relationships are gained bythe use of unsaturated fatty acids and, more especially, by employingunsaturated hydroxy fatty acids. Suitable materials include thefollowing: capric acid, undecylic acid, lauric acid, myristic acid,stearic acid, oleic acid, 9-, 10-, 11-, 12-, or 13- hyciroxy stearicacids, 10-, or l5-hydroxy palmitic acids, lO-hydroxy myristic acid,5,6-dihydroxy stearic acid, 2,1l-dihydroxy palmitic acid, 12- hydroxyoleic (ricinoleic) acid, 12-hydroXy-9,l0- hexadecenoic(palmitoleic)acid,and l2-hydroxy- 9,10-tetradecenoic(myristoleic) acid.

The above types of fatty acids are to be reacted to form soaps withalkanolamines having less than six carbon atoms per alkanol radical and,preferably, with trialkanolamines. The most commonly available speciesand one which has been found to give satisfactory results istriethanolamine. Other species suitable for the present purpose areexemplified by the following list: mono-ethanolamine, di-ethanolamine,diamino-isopropanol, di-n-propanolamine, tri-isopropanolamine,butanolamines.

It will be apparent from the list of alkanolamines and higher fattyacids given above that the preferred type of soap comprises the soap ofa trialkanolamine with an unsaturated hydroxy fatty acid having morethan twelve carbon atoms in the molecule. However, derivatives ofcertain 3 4 natural products may be employed as Well. For presence ofthe additional fluid, such as that cl example, the triethylene aminesoap of hydroscribed hereinafter as a water soluble Ucon genated castoroil acids is suitable in addition to fluid improves the gasolineresistance of the the following typical soaps: grease and, moreover,enables it to be used at Triethanolamine r1 cinoleate 5 lowtemperatures, such as occur at higher alti- Diethanolamine ricinoleatetudes, in the order of 65 without becoming T1,i isopmpaho1ammericinoleate unduly sti ii. The water soluble fluids are pref-Monmbutanolamine ricinoleate erably those composed to a large extent ofoxy- Triethanolamine lg hydroxysteamt alkylene units wherein the unitcontains from Triethanolamine;Wmwlroxy myristate two to ten carbonatoms. The best fluid for the Triethanolamine g,lo;dihydmxy palmitatepresent purpose comprises the mono--ethers of Triethanolami-ne 12hyd1.0Xy palmitoleate oxyalkylene polymers such as the lower monovalkylene others of 'polyalkylene oxides and gly- The Partial @8736"cols. In addition to the ethers of polyalkylene The fluid components ofthe present gasoline 15 Oxides or glycols, esters may be employed andresistant greases comprise two essential types. the polymers may beeither homwpolymers The first of these is a partial ester "er a pei @"Wmore monomeric QXides hydr y alcohol, said alcohol having f twoglycol's. Among these will be found trimethylene to ten carbon atomswith higher fatty acid-s. glycol ethylene glycol copglymsrs of ethyleneOptimum results are obtained by the use of polyglycol and propyleneglycol, co'pfilymers of liydric alcohols having from two to five carbonethylsne Oxide and l'propylene Oxide and the atoms and, preferably, areglycol or glyceryl parlikeftia esters er unsaturated fatty acids, thelatter It has b found that useful and improved having at least twelvecarbon atoms per m-olepolwxyalkylene d t of relatively high aver m IMespscigmyy n gasoline resist age molecular weight, which are essentiallymixy t pe ti are b d the use of e tures of true monohydroxy alcohols,may be obtialglyceryi esters of unsaturated hydroxy fatty mined by theaddition to a mOnOh-YdYOX-V acidgi T v list which f u presents typicalphatic alcohol or a mixture of alkylene oxides partial esters suitablefor use in the present eontainmg ethylene Oxide and lpl'opylene oxidegreas in a ratio preferably from about 50:50 to 75:25 Glycervlmoxlorijcanoleafe ethylene oxide to 1,2-propylene oxide. By thisGlycoljmon g Q or r de ratio is meant that in the oxide n'nxture, ehtaerthritormororioin 1 t which may be used in forming such monohy T y 0 ea 9droxy alcohol addition products, the amount of G y c y' Q m 55l,2--propylene oxide in the mixture is from V; to Carbitol ricinoleate(monoricmoleate of diethylan equal amount 0f ethylene Oxide present byene glycol monoethyl ether) weight.

ai l r gzzte The reaction which takes place between the glyceryhmqno(lzhydroxysteamte) alcohol and the ethylene ox1de and propylene 40 oxideseems to "be a simple addition wherein the alkylene oxide moleculesundergo conversion to the corresponding oxyalkyl'ene radicals as illus-Glyceryl-mono 9, lo-dihydroxypalmitate) Glyceryl-mono (12-hydroxypalmitoleate it will be noted that the above types ofpartialHated fcr y given molecule by t e followin esters com-prise not only thesimple partial esters general equatloni vof'pblyhydric alcohols withhigher fatty acids but Ro-H +a/( o Eco +'z (O-Ha.-C2H oymroonmomu alsocomprise the partial esters of high fatty 0 Alcohol 5 a oxid p vlene1,2-propylen'e Addition acids with 'mo'no-ethers of pol'yhydricalcohols. e Oxide p o tsetse are e r'elnplifi'ed by the C'arbitolricinotea e. The Carbi-to'l is understood to be 'die'thylene "glycolmonoethyl ether. Other ethers suitable -for this purpose includediethylene glycol me'netatyi ther, diethylene glycol monoethylenethe'rand the mono-others of alkylene glycols such as ethylene glycolmonobutyl ether.

wherein ROH is ail-aliphatic monohydroxy alcohoi; y and 2 represent the'mol's of ethylene oxids and 1-,2-propyle'n'e oxide, respectively; rt isboth 2 and '3 inasi'ng'le molecule, the total number of times 11 has avalue of 2 being'equal to y and the total number of times-n has a valueof 3 being equal to e; and a: is the total number The pozyowazkylenefluids or 'such oxyalk-yle'n'e groups, being equal to gH-z. I Thesepolymers are preferably mono-etriers of he t d ess fl ponentoi thepresent polyoxyallrylene glycols with nionoliydric ali-= gasolineresistant grease compositions comprises phatic alcohols having from oneto six-carbon water soluble 'pol'yo'xyalkylene fluids. It is deatoms andpreferably from two to five. The sirabl'e, or course, to have this fluidnot only be molecular "tv'eight isip'referably between biiland solublein water but also miscible with the par- 1500. A typical example of thisseries comprises tial esters discussed hereinbefore. Preferably the-mixture of 'nionohydroxy oxyalltylene, oxythey'should have a volatilitycomparable to a me- 11,2-propylene butylmono-ethers-having anaveriiiu'm'visc'osity lubricating oil but the latter propage molecularweight "of between 500 and i580 erty is no't'as important as itssolubility in water 5 in which the ethylene oxide and LIE-propylene andits lack of solubility in gasoline or other light oxide are combinedtherein as "oxyethylene and hydrocarbons. The principal function ofthese oxy-LZ-propylene groups in-aratio oi part of fluids comprises theimprovement of resistance to '1,'2-propylene oxide for each part byweight of washingaway, by gasoline or the like, of theparethylene oxide,the mono-ethers oi'isaid mixture tial esters and at the same time theimprovement containing in i a single molecule both the oxyin the lowtemperature operating characteristics "alkylene and oxy-LZ-propylenegroups. of the grease. It has been found that greases The 'fluids'whichhave been foun'dto be percomprising the ester and soaps, such astriethticularly suitable should have viscosities of beanolam'inericinoleate, operate fairly satisfactorily tween about 50- and 2,000SUS-at 100 F. They only at ro'o'r'n temperature or slightly below. The vusually have viscosityindexes' v/hich'vary about 90 to 150. The pourpoints of the lower viscosity members, which are preferred, are betweenabout -90 and --40 F. Their flash points, open cup, are between about250 and 450 F. They have fire points, open cup, between about 275 and550 F. The preferred varieties are those which have a viscosity betweenabout 50 and 250 SUS at 100 F.

The greases The greases of the present invention comprise the threeessential ingredients in the following proportions:

Amine soap: 5-25% by weight Water soluble polyoxyalkylene fluid: -50% byweight Partial ester: 30-60% by weight When proportions of this varietyare employed a wide variety of greases may be obtained for particularpurposes. Using amounts of soaps between 12 and 20%, one may obtain agrease having a medium consistency and which maintains a lubricatingquality even at extremely low temperatures such as lower than 40 F. Itis preferred that the weight ratio of polyoxyalkylene fluid to thepartial ester be between 2:5 and 4:5. The best results are obtained whenthe polyoxyalkylene fluid comprises -40% of the grease and the partialester comprises between 55 and 35% .by weight of the grease. Theexamples which. follow illustrate typical compositions of the presentinvention:

Example 1- Percent by weight Triethanolamine ricinoleate 20:-

50 HB 100 Ucon fluid Glyceryl monoricinoleate 50:

Example II- Triethanolamine ricinoleate I5 50HB 100 Ucon fluid 33;

Glycol monoricinoleate 52.

Example III- Triethanolamine ricinoleate lo 50 HB 100 Ucon fluid 30Pentaerythritol monoricinoleate 60 Example IV-- Triethanolaminericinoleate 25 50 HB 100 Ucon fluid 20- Diethylene glycolmonoricinoleate 55 Example V- Triethanolamine ricinoleate 20 50 HB 100Ucon fluid 50 Carbitol monoricinoleate 30 Example VI- Triethanolaminericinoleate 20 50 HB 100 Ucon fluid 35 Glyceryl diricinoleate ExampleVII- Diethanolamine ricinoleate 18 HB 100 Ucon fluid 37 Glycerylmonoricinoleate 45 Example VIII- Ethanolamine ricinoleate 22 50 HB 100Ucon fluid :28

Glyceryl monoricinoleate 50 Example IX- Di-n-propanolamine ricinoleate16 50 HB 100 Ucon fluid 30 fit) Glyceryl monoricinoleate 54 7 Example X-Percent by weight Triethanolamine-12-hydroxystearate 12 50 HB Ucon fluid34 Glyceryl monoricinoleate 54 Example XI'I'riethanolamine-Q,lo-dihydroxystearate 20 50 HB 100 Ucon fluid 30Glyceryl monoricinoleate 50 Example XII-- I Triisopropanolaminericinoleate 20 50 HB 100 Ucon fluid 30 Glyceryl monoricinoleate 50Example XIII- Triethanolamine ricinoleate 25 50'HB 55 Ucon fluid 20Glyceryl monoricinoleate 55 Example XIV- Triethanolamine ricinoleate 550 HB 660 Ucon fluid 45 Glyceryl monoricinoleate 50 Example XV-Triethanolamine ricinoleate 20 Poly(propylene glycol) mol. wt. 250 30Glyceryl monoricinoleate 50 Example XVI- Triethanolamine ricinoleate 20Poly(trimethylene glycol) mol. wt. 300 30 Glyceryl monoricinoleate 50Example XVII- Triethanolamine ricinoleate 20 -ester of butyric acid andpoly(ethylene glycol-propylene glycol) mol. wt.

325 30 Glyceryl monoricinoleate 50 Example XVIII- Triethanolaminericinoleate 20 A; butyl ether of poly(ethylene glycolpropylene glycol)mol. wt. 600 30 Glyoeryl monoricinoleate 50 Example XIX Triethanolaminericinoleate 20 50 HB 100 Ucon fluid 30 Glyceryl mono-12-hydroxystearate50 Example 2Q;-

Triethanolamine ricinoleate 20 50 HB 100 Ucon fluid 30 Glycerylmono-(9,10-dihydroxystearate) 5 Example XXI-- Triethanolaminericinoleate 19 50 HB 100 Ucon fluid 33 Glyceryl monoricinoleate 47.5Phenyl alpha-naphthylamine 0.5

.Example XXII- Triethanolamine ricinoleate 18.0 50 HB 100 Ucon fluid32.0 Glyoeryl monoricinoleate 47.0 Phenyl alpha-naphthylamine 0.5 -Oleicacid salt of 2-heptadecyl-hydroxymethyl-l-ethyloxazoline 2.5

"The oxidation and corrosion characteristics o'f these compositions areimproved to an outstanding extent by the inclusion of a combinaftion .of:an aromatic amine and a higher fatty acid:salt of a substitutedoxazoline having the generalnonfiguration:

R1\ /N=C-Rz R, on-o attests wherein'zRl anda-Rz are hydrogen, alkylnhdmxyr alkyl, .arylor :acyloxyalkyhradicals.andfiRs and R4 are .eitherhydrogen .or :alkyl rsuhsti ll Typical .members of tthis group ,willl-bfi (found in U. S. Patent 2,402,791. Additives which gney b employedn 1.de- .ee 9i l1 Jimrin least six carbon atoms andflprefer or morecarbon atoms. ,Ifheygnay be saturated or unsaturated acids and,"furthermore, may contain hydroxy groups resulting inqa hydroxy fattyacid. Typical speeiescmeeting these requirementsinclude caprioacidlauric acid, myristic 7 acid, oleic acid, tstearic acid, =l2ehydroxyoleic acid, 12-hydroxy stearic acl d and,.rnixtures of acids from n turaggl st-ide 3191; aslfish oil fatty acids, coconut ,oi1,atty acids, anfrom animal fats andpils. ,Iypical o which may be utilized in saltformation with the above acids include the following:-the oxazolinesutilized 'inpreparing the products Lon the-present invention maybeanyof'a number of such compounds, as i for examp1e,-2 ethyl -.41hydroxymethyl 4 methyloxazoline, 2 i s op ropyl.. {ihydroxymethyl 4 rne;thylqxaxoline ZJ-heptyl- 4 hydroxyrnethyl 4 je hy az ohne, 2'tridecyl 4 hydroxymethyl methy'lo v aaqline, 2 octyl 4 hyd'roxym'ethyl 4ethyloxazoline, 2 hendecyl 4 hydroxymethyl 4 methyloxazoline, 2--hendecyl 4 -hydroxyme-thyl 4 ethyloxa-zoline,Z-heptyI-i-Khydroxyrnethyl) oxazoline,- Z-heptyl 4,4 --bis(hydroxyrnethyl) Q oxazoline, 2-octyloxazo1ine, 2-hendec-yl-4 4 bisthy-2-hendecyl-4,.4-din1 h it b e "s l h l .aqi a rhflllil. i t y a o ne thclzihzdres of 2- ethyl -4- hydr oxymethyl -4- r n yloxaaolinc and thestearlc acid salt of; a des 521;44- dimethyloxazoline.

The aromatic amines to be combined with these oxazoline salts include;particularly, polycycloamines of whichthe'pr'eferred species isphenylalpha-naphthylamine. It is preterged that the group contaimat;leastnonecphenyl gradical andthat inaddition-theretd another h carbongronpgor;i substituted hydrocarbon gr be directly attached to thenitrogen atom. Tlj ese amim siaiberem e QQQ rEEQP having the structuralcon figu wherein R is a hydrocarbon or a substituted bydrocarbonradical. Typical species dinclude phenyl beta naphthylamine,..-dipheny1amine, phenylstearylamine and: the :like.

. We claim as our invention:

1. A gasoline-resistant grease-comprising a gelling amount of.ihydrioxyalkylaminessoapIiof a higher .fatty acid, :20-50% .by,. weightof; a water acids gthylen and.oXy-..l,2-propylenegroups ina ratio fmmabout one-third .to' .one part .1,2-propy1en. oxide. for ,each part .of.ethylene oxide "by weight, the monoethers of saidrnixture containing ina single .molecule both the .oxyethylene and goxy- 1,2 propylene groupsand. 30-60,% iby.,w.eight ,of glyceryl ,monoricinoleate.

3. A gasoline-resistant grease comprising a gelling amount of "a"hydro'xyalkylamine soap of an .unsaturatedfiatty .acid, .30-50 t byWeight of almixtu'rfe crmonchydrqxy vcxyethylen foxy-1,2- propylenebutyfmonoeth'er's' an'. verage molecular weight of at least 900 inwhich'ethylene oxide and Lz-pr'opylene QXideare combined therein asoxyethylene land .oxy-LZ-propyl'ene groups in a ratio from one part tonine partsof 1,2-propylene oxide l-for ,each part of ethylene oxide, byweightthe monoethers of said mixture containingin a single molecule boththeoxyethylene and the oxy-Lz-propylen group, and 30-60 weight ofapartial este'rof 'g1yceririe anda fatty acid having at least twelvecarbon atoms.

4; A gasoline-resistant grease comprising a gelling proportion of ahydroxyalkylamine soap ofan iinsaturated' hydroxy fatty acid, 30-50% byweight of a mixture of 'monohydroxy oxyethylene oXy LZ-p-ro lene butyl'monoethers having an average mo ecular :weight of atileast 900 inwhichiethyleneo ide and Jig-propylene oxide arecombined thereina'soxyethylen'ean'd oxy-1,2-propylenegroupsfin a ratio frjorn' oiie part tonine parts of 1,2-propylen'e' oxide for each part of ethylene oxide, byweight, the nonoethers ofsa id mixturenontaining in a singlernolecul eboth the ox'yethylene andthe. voxy- 1,2 -p r0pylene group, and 30-60% byweightbta partial ester of glycrine' and an. "unsaturated fatty acid.having at'l'ea's't twelvecarbbn atoms.

fat ci 7 A;ses l e is antgrace r m a propylene oxide are combinedtherein as oxy- 5. A gasoline-resistant grease comprising a gellingamount..of..a.hydroxyalkylamine soap of an unsaturated,,hydroxylfattyacid having at least twelve. carbon atoms", -50% by weight of a mixtureof monohydroxy oxyethylene orgy-1,2- pr opylene butyl monoethers havingffa'n average molecular weight of "at least 900 in, w hi ch ethyleneoxide and 1,2-propylehe oxide are'comb-ined therein as oxyethyleneand"oxy-'1,2-prop'ylene groupg in a ratio from one part to nine parts 2.1 1 93 93 5 l h ar 9 th l oxide, by weight, the n onoethers of,saidmixture eq ta a ne i I a s n l m ecu ot h pa ethylene and theoxy-1,2propylene group, and -60% by weight of a partial ester of'glycerine and anunsaturatedfatty' acid having "at least twelve carbonatoms.

'6. A gasoline-resistant grease comprising a gelling amount oftriethanolamine soap, of an unsaturated hydroxy fatty acid having,at'least twelve carbon atoms, '3'0-50 b'y. weigl'it of a mixture ofmonohydrox'yoxyethylene' oxy l,2:propylene butyl nionoethefs" having "an"average moneular weight of a least 900 in which ethylene oxide and.1,2.-.pro.pylene oxide are combined therein .as ,.oxyethylene andoxy-l,2-propylene groupsin..a.ratio.from.onelpart to nine parts of1,2-propylene oxide for each part of ethylene oxide, by weight, themonoethers of said. mixture containing in a singlemolculeiboththejoxyethylene and the oxy-l', 2 -propy lene group, and

;; sql il ah 'wl iiip j aaaitamami seaap an 9 unsaturated hydroxy fattyacid having at least twelve carbon atoms, 30-50% by weight of a watersoluble polyoxyalkylene fluid and 30-60% by weight of glycerylmonoricinoleate.

8. A gasoline-resistant grease comprising a gelling amount oftriethanolamine ricinoleate, 30-50% by weight of a water solublepolyoxyalkylene fluid and 30-60% by weight of a partial ester of anunsaturated higher hydroxy fatty acid and 01' a polyhydric alcoholhaving less than four carbon atoms.

9. A gasoline-resistant grease comprising a gelling amount of analkanolamine soap of an unsaturated hydroxy fatty acid having at leasttwelve carbon atoms, 30-50% by weight of a water soluble polyoxyalkylenefluid, and 30-60% by weight or a glyceryl monoester of a, fatty acidhaving at least twelve carbon atoms per molecule.

10. A gasoline-resistant grease comprising a gelling amount oftrialkanolamine ricinoleate, 30-60% by weight of glycerylmonoricinoleate and 20-50% by weight of a mixture of monohydroxyoxyethylene oxy-1,2-propylene butyl monoethers having an averagemolecular weight of at least 900 in which ethylene oxide and 1,2-propylene oxide are combined therein as oxyethylene andoxy-1,2-propylene groups in a ratio from one part to nine parts of1,2-propylene oxide for each part of ethylene oxide, by weight, themonoethers of said mixture containing in a single molecule both theoxyethylene and the oxy-1,2-propylene group, said composition alsocontaining minor amounts sufficient to improve the oxidation andcorrosion characteristics thereof of phenyl-alpha-naphthylamine and of 4wherein R1 and R2 are substituents of the group consisting of hydrogen,and alkyl, hydroxyalkyl, aryl and acyl-oxyalkyl radicals and R3 and R4are radicals of the group consisting of hydrogen,

and alkyl substituents.

HAROLD A. WOODS. LOREN C". BOLLINGER.

References Cited in the file of this patent UNITED STATES PATENTS NumberName Date 2,083,132 Williams et al June 8, 1937 2,425,845 Toussaint eta1 Aug. 19, 1947

1. A GASOLINE-RESISTANT GREASE COMPRISING A GELLING AMOUNT OFHYDROXYALKYLAMINE SOAP OF A HIGHER FATTY ACID, 20-50% BY WEIGHT OF AWATER SOLUBLE POLYOXYLALKYLENE FLUID AND 30-60% BY WEIGHT OF A PARTIALESTER OF A POLYHYDRIC ALCOHOL HAVING LESS THAN SIX CARBON ATOMS WITH AHIGHER FATTY ACID.